JP5435310B2 - Rotating electrical machine control device and steering control system using the same - Google Patents

Description

  The present invention relates to a rotating electrical machine control device and a steering control system using the same.

  2. Description of the Related Art Conventionally, a steering control system using a rotating electrical machine as a drive source for a vehicle power steering apparatus is known. For example, Patent Document 1 discloses an electric power steering apparatus using a rotating electrical machine driven by PWM (Pulse Width Modulation) control as a drive source. The rotating electrical machine used here is a brushless motor having three-phase windings, and the drive is controlled by a rotating electrical machine control device including a switching element and the like.

JP 2009-1217 A JP-A-11-29054

  By the way, in a rotating electrical machine control apparatus that performs PWM control, when stopping the driving of a brushless rotating electrical machine having a plurality of phases of windings, the duty ratio of the voltage applied to the windings of each phase is 50%, and In general, control is performed so that the current flowing to the rotating electrical machine is zero by applying a voltage to the windings of each phase at the same timing. Here, even if control is performed so that the current flowing to the rotating electrical machine becomes zero, due to the parasitic capacitance of the rotating electrical machine, the common mode current (hereinafter referred to as “common mode current”) at the timing of applying the voltage and the timing of releasing the voltage application ") May flow like a spike. In particular, when a voltage is applied to the windings of each phase at the same timing, common mode currents may overlap and a large spike current may flow. As a result, large electrical noise is emitted as radio noise, which may affect other devices.

  Therefore, in the electric power steering device of Patent Document 1, an attempt is made to reduce the above-described radio noise by providing a filter circuit in the rotating electrical machine control device that drives the rotating electrical machine. As a countermeasure against radio noise, a method of adding a snubber circuit, a method of adding a shield wire, a method of using a coaxial cable as disclosed in Patent Document 2, and the like have been proposed. However, in the case of countermeasures by these methods, there is a problem that the cost for the countermeasures increases because the number of members is large and the configuration becomes complicated.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a rotating electrical machine control device capable of reducing radio noise generated when driving of the rotating electrical machine is stopped with a simple configuration, and the same. The object is to provide a steering control system.

  The invention according to claim 1 is a rotating electrical machine control device for controlling a rotating electrical machine having a winding set composed of a plurality of phase windings, wherein the target current value calculating means, the PWM signal generating means, the voltage applying means and the control are controlled. Means. The target current value calculation means calculates a target current value to be passed through the winding of each phase. The PWM signal generating means generates a pulsed PWM signal for each phase winding based on the target current value calculated by the target current value calculating means. The voltage applying means applies a voltage to the windings of each phase based on the PWM signal generated by the PWM signal generating means. The control means controls the drive of the rotating electrical machine by controlling the target current value calculating means, the PWM signal generating means, and the voltage applying means.

  In the present invention, when the control means controls to stop driving the rotating electrical machine, the timing of the pulse change of the PWM signal of at least one phase is different from the timing of the pulse change of the PWM signal of the other phase. The PWM signal generation means is controlled so that the PWM signal is generated. Thereby, it is possible to avoid the rise timing or fall timing of the PWM signal of at least one phase from overlapping with the rise timing or fall timing of the PWM signal of another phase. For this reason, it is possible to avoid that the application timings of the voltages applied to the windings of the respective phases by the voltage applying means all overlap. As a result, it is possible to avoid the common mode current flowing in the rotating electrical machine from being overlapped with one another. Therefore, it is possible to reduce radio noise generated from the rotating electrical machine control device or the rotating electrical machine when driving of the rotating electrical machine is stopped.

Thus, in the present invention, radio noise can be reduced by control. That is, in the rotating electrical machine control device of the present invention, radio noise can be reduced with a simple configuration without using radio noise countermeasure members such as a filter circuit, a snubber circuit, a shielded wire, and a coaxial cable.
According to the first aspect of the present invention, when the control means performs control to stop the driving of the rotating electrical machine, the target current value to be passed through the winding of at least one phase is calculated to a non-zero predetermined value. By controlling the target current value calculation means, the PWM signal is generated so that the pulse change timing of the PWM signal of at least one phase differs from the pulse change timing of the PWM signal of the other phase. Control the signal generating means. Here, the non-zero predetermined value is a non-zero predetermined value that is small enough not to affect the driving of the rotating electrical machine.
The present invention exemplifies a specific control method of the target current value calculating means when generating PWM signals having different pulse change timings by the PWM signal generating means. By applying a small current that does not affect the driving of the rotating electrical machine to the winding of at least one phase, the timing of pulse change of the PWM signal generated by the PWM signal generating means can be shifted, and voltage application The application timing of the voltage applied to the winding can be shifted by the means. Therefore, it is possible to reduce radio noise generated from the rotating electrical machine control device or the rotating electrical machine when driving of the rotating electrical machine is stopped.

  In the invention according to claim 2, when the control means performs control to stop the driving of the rotating electrical machine, the pulse change timings of the PWM signals of all the phases and the pulse changes of the PWM signals of the other phases are controlled. The PWM signal generation means is controlled so that the PWM signal is generated so that the timings are different from each other. As a result, the rising timing or falling timing of the PWM signals of all the phases and the rising timing or falling timing of the PWM signals of the other phases are both shifted (made different). it can. For this reason, it is possible to reliably avoid the application timings of the voltages applied to the windings of the respective phases by the voltage applying means overlapping. Accordingly, it is possible to further reduce radio noise generated from the rotating electrical machine control device or the rotating electrical machine when driving of the rotating electrical machine is stopped.

  According to a third aspect of the present invention, the timing of the pulse change is at least one of the rising timing of the PWM signal and the falling timing of the PWM signal. When the timing of the pulse change is both the rise timing of the PWM signal and the fall timing of the PWM signal, the rise timings of the voltages applied to the windings of the respective phases by the voltage applying means overlap. , And the overlapping of the falling timings can be avoided. Therefore, the radio noise generated from the rotating electrical machine control device or the rotating electrical machine when driving of the rotating electrical machine is stopped can be further reduced.

In the invention according to claim 4 , when the control means performs control to stop the driving of the rotating electrical machine, the target current value to be passed through the windings of all the phases is calculated to be a predetermined value that is not zero. By controlling the current value calculation means, the PWM signal is generated so that the pulse change timings of the PWM signals of all the phases are different from the pulse change timings of the PWM signals of the other phases. Controls the PWM signal generation means.

The present invention exemplifies a specific control method of the target current value calculating means, as in the first aspect of the present invention. By passing a small current that does not affect the driving of the rotating electrical machine to all the windings of each phase, the timing of the pulse change of the PWM signal generated by the PWM signal generating means can be reliably shifted, The application timing of the voltage applied to the winding by the voltage applying means can be shifted reliably. Accordingly, it is possible to further reduce radio noise generated from the rotating electrical machine control device or the rotating electrical machine when driving of the rotating electrical machine is stopped.

In the invention according to claim 5 , the control means applies the voltage applied to the winding of at least one phase and the winding of the other phase when controlling to stop the driving of the rotating electrical machine. The voltage applying means is controlled to apply the voltage so that the voltage application timing is different. Therefore, it is possible to reduce radio noise generated from the rotating electrical machine control device or the rotating electrical machine when driving of the rotating electrical machine is stopped.

In the invention according to claim 6 , when the control means controls to stop the driving of the rotating electrical machine, the application timing of the voltage applied to all the windings of each phase and the application to the windings of each other phase The voltage application means is controlled to apply a voltage so that the voltage application timings are different from each other. Accordingly, it is possible to further reduce radio noise generated from the rotating electrical machine control device or the rotating electrical machine when driving of the rotating electrical machine is stopped.

A seventh aspect of the present invention is a steering control comprising: the rotary electric machine control device according to any one of the first to sixth aspects; and the rotary electric machine attached to a member for turning a steering wheel of a vehicle. System. That is, in the present invention, the rotating electrical machine control device and the rotating electrical machine constitute, for example, an electric power steering device as a steering control system.

The invention according to claim 8 includes the rotating electrical machine control device according to any one of claims 1 to 6 and the rotating electrical machine attached to a member that steers a wheel different from a steering wheel of the vehicle. A steering control system provided. Usually, the steering wheel of a vehicle corresponds to the front wheel. Therefore, in this invention, the structure which attaches a rotary electric machine to the member which steers a rear wheel can be considered. That is, in the present invention, the rotating electrical machine control device and the rotating electrical machine constitute a rear wheel steering device as a steering control system in a four-wheel steering vehicle, for example.

The invention according to claim 9 is the rotating electrical machine control device according to any one of claims 1 to 6 , the first rotating electrical machine attached to a member for turning the steering wheel of the vehicle, and the steering wheel. And a second rotating electric machine attached to a member that steers wheels different from the steering control system. That is, in the present invention, the rotating electrical machine control device and the first rotating electrical machine constitute an electric power steering device, for example, and the rotating electrical machine control device and the second rotating electrical machine constitute, for example, a rear wheel steering device. .

In the inventions according to claims 7 to 9 , since the radio noise generated from the rotating electrical machine control device or the rotating electrical machine when driving of the rotating electrical machine is stopped can be reduced, the noise caused by the radio noise is output from the radio of the vehicle. Can be suppressed.

The schematic diagram which shows the rotary electric machine control apparatus by 1st Embodiment of this invention. The schematic diagram which shows the electric power steering apparatus to which the rotary electric machine control apparatus by 1st Embodiment of this invention is applied. (A) is a diagram showing a PWM signal generated when the rotating electrical machine control device according to the first embodiment of the present invention stops driving the rotating electrical machine, (B) is a diagram showing a part of (A), (C) Is a diagram showing the common mode current flowing through the rotating electrical machine for each phase, and (D) is a diagram showing the common mode current flowing through the rotating electrical machine. (A) is a diagram showing a PWM signal generated when the rotating electrical machine control device according to the comparative example stops driving the rotating electrical machine, (B) is a diagram showing a part of (A), and (C) is flowing through the rotating electrical machine. The figure which shows a common mode current for every phase, (D) is a figure which shows the common mode current which flows into a rotary electric machine. The schematic diagram which shows the rotary electric machine control apparatus by 2nd Embodiment of this invention.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In the plurality of embodiments, substantially the same members or parts are denoted by the same reference numerals, and description thereof is omitted.
(First embodiment)

  A rotating electrical machine control apparatus according to a first embodiment of the present invention is shown in FIG. The rotating electrical machine control device 21 is used to control driving of the motor 10 as a rotating electrical machine. As shown in FIG. 2, the motor 10 is used as a drive source of the electric power steering apparatus 1 mounted on the vehicle. That is, the rotating electrical machine control device 21 and the motor 10 are part of the components of the electric power steering device 1.

  A gear 3 is provided on the column shaft 2. A steering 4 as a steering member is attached to one end of the column shaft 2. A torque sensor 5 is provided between the gear 3 of the column shaft 2 and the steering 4. A pinion gear is provided at the end of the column shaft 2 opposite to the steering 4, and the pinion gear meshes with a gear formed on the rack 6. Both ends of the rack 6 are connected to a front wheel 7 as a steering wheel of the vehicle. As a result, when the vehicle occupant rotates the steering wheel 4, the steering torque is transmitted to the column shaft 2, and the front wheel 7 is steered by moving the rack 6 in the longitudinal direction. In other words, the column shaft 2 is one member for turning the front wheel 7.

  The motor 10 is attached so that the end of the motor shaft 17 meshes with the gear 3 provided on the column shaft 2. The rotating electrical machine control device 21 rotates the motor 10 forward and backward based on a torque signal output from the torque sensor 5 that detects the steering torque of the steering 4 and a vehicle speed signal acquired from a CAN (Controller Area Network) (not shown). As a result, an assist force related to steering is generated.

  As shown in FIG. 1, the motor 10 has windings 11, 12, 13 and the like. In the present embodiment, the motor 10 is a general three-phase brushless motor. The windings 11, 12, and 13 are wound around a stator (not shown) that is housed and fixed in the motor case 14 to constitute one winding set (101). A rotor (not shown) is provided inside the stator so as to be rotatable relative to the stator. A motor shaft 17 is provided at the rotation center of the rotor. The motor shaft 17 is rotatably supported by the motor case 14. That is, the rotor is rotatably supported by the motor case 14 via the motor shaft 17.

The windings 11, 12, and 13 are Y-connected. The windings 11, 12, and 13 correspond to the U phase, the V phase, and the W phase in the motor 10, respectively. The connection point of the windings 11, 12, 13 is a neutral point p1. The motor 10 is driven to rotate by the electric power supplied to the windings 11, 12, 13 being controlled by the rotating electrical machine control device 21. Moreover, in this embodiment, the motor 10 has the rotation angle sensor 15 which detects the rotation angle with respect to the stator of a rotor.
The rotating electrical machine control device 21 includes an inverter 30, a control IC 40, and the like.

  The inverter 30 includes switching elements 31 to 36 and the like. In the present embodiment, the switching elements 31 to 36 are MOSFETs (metal-oxide-semiconductor field-effect transistors) which are a kind of field effect transistors. The switching elements 31 to 36 are ON / OFF controlled between the source and the drain by the gate voltage.

In the switching elements 31 to 33 on the upper arm side, the drain is connected to the power supply 8 side, and the source is connected to the drains of the corresponding switching elements 34 to 36 on the lower arm side. The sources of the switching elements 34 to 36 on the lower arm side are connected to the ground side. Connection points between the upper arm side switching elements 31 to 33 and the corresponding lower arm side switching elements 34 to 36 are electrically connected to the windings 11, 12, and 13 of the motor 10 by motor lines 111, 121, and 131, respectively. Connected. Here, the switching element pair including the switching element 31 and the switching element 34 corresponds to the U phase. A switching element pair composed of the switching element 32 and the switching element 35 corresponds to the V phase. A switching element pair composed of the switching element 33 and the switching element 36 corresponds to the W phase.
A shunt resistor 37 is provided between the switching elements 34 to 36 and the ground. By detecting the voltage applied across the shunt resistor 37, the current flowing through each phase of the motor 10 can be detected.

  The control IC 40 is a semiconductor integrated circuit including a microcomputer 41 and a pre-driver 42. The microcomputer 41 is a small computer having a CPU as arithmetic means and ROM and RAM as storage means. In the microcomputer 41, various processes are executed by the CPU according to various programs stored in the ROM. The microcomputer 41 corresponds to “control means” in the claims.

  The microcomputer 41 receives a signal related to the rotation angle of the motor 10 from the rotation angle sensor 15, information related to the voltage across the shunt resistor 37, a steering torque signal from the torque sensor 5, and vehicle speed information from CAN. When these signals are input, the microcomputer 41 controls the switching elements 31 to 36 via the pre-driver 42 based on the rotation angle of the motor 10. More specifically, the microcomputer 41 controls the switching elements 31 to 36 to be turned on / off by changing the gate voltages of the switching elements 31 to 36 by the pre-driver 42. Further, the microcomputer 41 controls the switching elements 31 to 36 so that the current supplied to the motor 10 approaches a sine wave based on the input voltage across the shunt resistor 37.

Next, the operation of the rotating electrical machine control device 21 of the present embodiment will be described more specifically.
The microcomputer 41 turns the motor 10 so that the motor 10 outputs a torque that assists the steering 4 in accordance with the vehicle speed, based on the vehicle speed information from the rotation angle sensor 15, the torque sensor 5, the shunt resistor 37, and the CAN. A target current value is calculated for the q-axis current that flows through the lines 11, 12, and 13. Here, the microcomputer 41 functions as “target current value calculation means” in the claims.

  The microcomputer 41 generates a pulsed PWM signal for each phase (windings 11, 12, 13) based on the calculated target current value and outputs it to the pre-driver 42. Here, the microcomputer 41 functions as “PWM signal generating means” in the claims.

  The pre-driver 42 generates a pulse signal based on the PWM signal input from the microcomputer 41. This pulse signal is output to the inverter 30 having the switching elements 31 to 36 to control the on / off switching operation of the switching elements 31 to 36. The voltage of the power supply 8 is applied to each of the windings 11, 12, and 13 by the on / off switching operation of the switching elements 31 to 36. Here, the pre-driver 42 and the inverter 30 function as “voltage applying means” in the claims.

  When the voltage of the power supply 8 is applied to each of the windings 11, 12, and 13, sinusoidal currents having different phases flow through the windings 11, 12, and 13 (each phase) of the motor 10 to generate a rotating magnetic field. . In response to this rotating magnetic field, the rotor and the motor shaft 17 rotate together. As the motor shaft 17 rotates, a driving force is output to the gear 3 of the column shaft 2 to assist the driver's steering by the steering 4.

Next, a control method for stopping the driving of the motor 10 by the rotating electrical machine control device 21 of the present embodiment will be described with reference to FIG.
In the present embodiment, when the microcomputer 41 performs control to stop the driving of the motor 10, first, the microcomputer 41 functions as a target current value calculation unit, and flows through the windings (11, 12, 13) of all the phases. The target current value is calculated to be a non-zero predetermined value. Here, the non-zero predetermined value is a predetermined value that is not zero and is a small value that does not affect the driving of the motor 10. That is, the current having the predetermined value is a small current that does not contribute to the output torque of the motor 10.

  The microcomputer 41 functions as a PWM signal generation unit, and generates a PWM signal for each phase based on the calculated target current value for each phase. Here, since the target current value of each phase is a non-zero value, the pulsed PWM signal generated by the microcomputer 41 is as shown in FIG. As shown in FIG. 3B, each phase of the PWM signal is generated such that the rising timing and falling timing are different. Note that the duty ratio of the PWM signal is about 50%.

  When the PWM signal shown in FIG. 3B is output from the microcomputer 41 to the pre-driver 42, the switching elements 31 to 36 of the inverter 30 are turned on and off. Thus, a voltage is applied to the windings (11, 12, 13) of each phase at the rising timing of the PWM signal. When a voltage is applied to or released from the windings (11, 12, 13) of each phase at approximately the same time, the timing of applying the voltage (PWM) due to parasitic capacitance such as a coil component and a resistance component of the motor 10 At the same time, the common mode current flows through the windings (11, 12, 13) of each phase at the timing of signal rise) and the timing at which application of voltage is released (PWM signal fall timing) (FIG. 1). reference). The common mode current flows in a spike shape.

  As shown in FIG. 3C, spike-shaped common mode current flows through the windings (11, 12, 13) of each phase at the timing of applying voltage (timing of rising of the PWM signal). In this embodiment, since the rising timings of the PWM signals are all shifted between the respective phases, the timings at which the common mode currents flow in the respective phases are all shifted in time. As a result, the total common mode current flowing through the motor 10 is relatively small as shown in FIG. Therefore, the generated radio noise is relatively small.

  As described above, spike-shaped common mode current flows through the windings (11, 12, 13) of each phase even at the timing of releasing the application of voltage (timing of falling of the PWM signal). In the present embodiment, since the falling timings of the PWM signals are all shifted between the phases, the timings at which the common mode currents flow in the phases are all shifted in time. As a result, the total common mode current flowing through the motor 10 is relatively small.

  As described above, in the present embodiment, when driving of the motor 10 is stopped, the target current value flowing through the windings of all the phases is calculated to be a predetermined value that is non-zero, so that The PWM signal is generated such that the pulse change timing of the PWM signal is different from the pulse change timing of the PWM signal of each other phase. Thereby, the inverter 30 applies a voltage so that the application timing of the voltage applied to all the windings of each phase differs from the application timing of the voltage applied to the windings of the other phases. As a result, the timings at which the common mode currents of the phases flow are all shifted in time, and the sum of the common mode currents flowing through the motor 10 is relatively small. Therefore, radio noise generated when the motor 10 is stopped can be reduced.

Next, an advantageous effect of the present embodiment over the comparative example will be clarified by describing a control method for stopping the driving of the motor 10 by the rotating electrical machine control device of the comparative example.
The rotating electrical machine control apparatus of the comparative example has the same physical configuration as that of the present embodiment. In the comparative example, when the microcomputer 41 performs control to stop the driving of the motor 10, the microcomputer 41 calculates the target current value flowing through the windings (11, 12, 13) of each phase to be zero.

  Then, the microcomputer 41 generates a PWM signal for each phase based on the calculated target current value for each phase. Here, since the target current value of each phase is zero, the pulsed PWM signal generated by the microcomputer 41 is as shown in FIG. As shown in FIG. 4B, each phase of the PWM signal is generated such that the rising timing and the falling timing all overlap. Note that the duty ratio of the PWM signal is 50%. That is, the control according to the comparative example is the same as a general control method for stopping the driving of the conventional three-phase brushless motor.

  When the PWM signal shown in FIG. 4B is output from the microcomputer 41 to the pre-driver 42, the switching elements 31 to 36 of the inverter 30 are turned on / off. Thus, a voltage is applied to the windings (11, 12, 13) of each phase at the rising timing of the PWM signal. At this time, due to the parasitic capacitance of the motor 10, the windings of the respective phases (timing of the rise of the PWM signal) and the timing of releasing the application of the voltage (timing of the fall of the PWM signal) ( 11, 12, 13) spike-like common mode current flows.

  As shown in FIG. 4C, spike-shaped common mode current flows through the windings (11, 12, 13) of each phase at the timing of applying voltage (timing of rising of the PWM signal). In the comparative example, since the rising timings of the PWM signals are all overlapped with each other, the timings at which the common mode currents flow in the respective phases coincide with each other in time. As a result, the total common mode current flowing through the motor 10 is relatively large as shown in FIG. Therefore, the generated radio noise is relatively large.

  As described above, spike-shaped common mode current flows through the windings (11, 12, 13) of each phase even at the timing of releasing the application of voltage (timing of falling of the PWM signal). In the comparative example, the falling timings of the PWM signals are all overlapped with each other between the phases, so that the timings at which the common mode currents flow in the respective phases coincide with each other in time. As a result, the total common mode current flowing through the motor 10 is relatively large.

  As described above, in the present embodiment, when the driving of the motor 10 is stopped, the application timing of the voltage applied to the winding is controlled so as to be completely different between the respective phases, thereby comparing with the comparative example (conventional example). The generated radio noise can be greatly reduced.

Next, the control when abnormality such as disconnection occurs in one phase of the rotating electrical machine control device 21 and the motor 10 of the present embodiment, that is, how to perform control at the time of abnormality will be described.
For example, when an abnormality such as an off failure occurs in the switching element 31 or the switching element 34 of the inverter 30 corresponding to the U phase, or when an abnormality such as a disconnection occurs in the winding 11 corresponding to the U phase of the motor 10. The rotating electrical machine control device 21 continues to drive the motor 10 with the other two phases (V phase and W phase). That is, at this time, the motor 10 is driven in two phases.

When the motor 10 is stopped when the motor 10 is driven in two phases as described above (control during abnormality), in this embodiment, the windings (12, 13) The target current value to be passed through is calculated so as to be a non-zero predetermined value.
The microcomputer 41 functions as a PWM signal generation unit, and generates a PWM signal for each phase based on the calculated target current value for each phase. Here, since the target current value of each phase is a non-zero value, the pulsed PWM signals (V phase and W phase) generated by the microcomputer 41 have different rising timings and falling timings, respectively. Is generated as follows. Note that the duty ratio of the PWM signal is about 50%.

  When the PWM signal is output from the microcomputer 41 to the pre-driver 42, the switching elements 32, 33, 35, and 36 of the inverter 30 are turned on and off. Thus, a voltage is applied to the windings (12, 13) of each phase at the rising timing of the PWM signal. When a voltage is applied to or released from the windings (12, 13) of each phase at approximately the same time, the timing of applying the voltage (the PWM signal) due to the parasitic capacitance such as the coil component and resistance component of the motor 10 The common mode current simultaneously flows in the windings (12, 13) of each phase at the timing of rising) and the timing of releasing the application of voltage (falling timing of the PWM signal). The common mode current flows in a spike shape.

  The windings (12, 13) of each phase are spiked at the timing of applying a voltage (rising timing of the PWM signal) and the timing of releasing the application of voltage (falling timing of the PWM signal). Common mode current flows. In this embodiment, the rising timing and falling timing of the PWM signal are shifted between the phases, and therefore the timing of the flow of the common mode current in each phase is shifted in time. As a result, the total common mode current flowing through the motor 10 is relatively small. Therefore, the generated radio noise is relatively small.

  As described above, in this embodiment, for example, when an abnormality occurs in a location corresponding to the U phase, the driving of the motor 10 is continued using the other two phases (V phase and W phase) as driving phases. Is calculated so that the target current value to be passed through the windings of all the phases (V phase, W phase) other than the driving phase becomes a non-zero predetermined value. The PWM signal is generated so that the pulse change timing of the PWM signal of one of the phases is different from the pulse change timing of the PWM signal of the other phases (the other of the V phase and the W phase). As a result, the inverter 30 applies the voltage applied to the winding of each phase (one of the V phase and W phase) and the voltage applied to the winding of each other phase (the other of the V phase and W phase). The voltage is applied so that the application timings of these are different. As a result, the timing at which the common mode current of each phase flows is shifted in time, and the total common mode current flowing in the motor 10 is relatively small. Therefore, even when the abnormality control is performed, it is possible to reduce radio noise generated when the motor 10 is stopped.

  As described above, in the present embodiment, when the microcomputer 41 performs control for stopping the driving of the motor 10, the pulse change timings of the PWM signals of all the phases and the pulses of the PWM signals of the other phases. The PWM signal is generated so that the timing of the change is different. As a result, the rising timing and falling timing of the PWM signals of all the phases and the rising timing and falling timing of the PWM signals of the other phases are both shifted (made different). it can. Therefore, it is possible to reliably avoid the application timings of the voltages applied to the windings 11, 12, 13 of each phase by the predriver 42 and the inverter 30 from overlapping. Therefore, radio noise generated from the rotating electrical machine control device 21 or the motor 10 when the driving of the motor 10 is stopped can be reliably reduced.

  In the present embodiment, the rotating electrical machine control device 21 and the motor 10 constitute a part of the electric power steering device 1 as a steering control system mounted on the vehicle. In this embodiment, since the radio noise generated from the rotating electrical machine control device 21 or the motor 10 when the driving of the motor 10 is stopped can be reduced, it is possible to suppress the noise caused by the radio noise from being output from the vehicle radio. .

  Further, in the present embodiment, when an abnormality occurs in a certain phase, an abnormal time control is performed in which the driving of the motor 10 is continued in another phase (drive phase). When the motor 10 is stopped when the control at the time of abnormality is performed, the target current value to be passed through each phase of the drive phase is calculated to be a non-zero predetermined value. Thereby, it can avoid that the application timing of the voltage applied to the winding of a drive phase overlaps. Therefore, even when the abnormality control is performed, it is possible to reduce radio noise generated when the motor 10 is stopped.

(Second Embodiment)
A rotating electrical machine control apparatus according to a second embodiment of the present invention will be described with reference to FIG. The second embodiment is different from the first embodiment in that a motor having two winding sets is controlled.

  The motor 50 to be controlled by the rotating electrical machine control device 22 of the present embodiment includes a second winding set including windings 51, 52, and 53 in addition to the first winding set 101 including windings 11, 12, and 13. 102. The windings 51, 52, and 53 are wound around a stator (not shown) that is housed and fixed in the motor case 14, similarly to the first winding set 101. The windings 51, 52, and 53 are Y-connected. The windings 51, 52, and 53 correspond to the U phase, V phase, and W phase in the motor 50, respectively. A connection point of the windings 51, 52, and 53 is a neutral point p2.

  In the motor 50, the electric power supplied to the first winding set 101 (windings 11, 12, 13) and the second winding set 102 (windings 51, 52, 53) is controlled by the rotating electrical machine control device 22. Rotation drive. In FIG. 5, for the sake of convenience, the first winding set 101 and the second winding set 102 are shown separately, but in reality, the first winding set 101 and the second winding set 102 are identical to each other. It is wound around one stator. That is, the motor 50 forms a redundant system by providing two systems with respect to the winding.

  The rotating electrical machine control device 22 includes an inverter 60 and a pre-driver 43 in addition to the inverter 30 and the pre-driver 42. The inverter 60 includes switching elements 61 to 66 and the like. In the present embodiment, the switching elements 61 to 66 are MOSFETs that are a kind of field effect transistor, like the switching elements 31 to 36.

  The connection form of the switching elements 61 to 66 is the same as that of the switching elements 31 to 36. Connection points between the upper arm side switching elements 61 to 63 and the corresponding lower arm side switching elements 64 to 66 are electrically connected to the windings 51, 52, and 53 of the motor 50 by motor wires 511, 521, and 531, respectively. Connected. Here, the switching element pair including the switching element 61 and the switching element 64 corresponds to the U phase. A switching element pair including the switching element 62 and the switching element 65 corresponds to the V phase. A switching element pair composed of the switching element 63 and the switching element 66 corresponds to the W phase.

  A shunt resistor 67 is provided between the switching elements 64 to 66 and the ground. By detecting the voltage applied across the shunt resistor 67, the current flowing through each phase of the second winding set of the motor 50 can be detected.

  The microcomputer 41 receives a signal related to the rotation angle of the motor 50 from the rotation angle sensor 15, information related to the voltage across the shunt resistors 37 and 67, a steering torque signal from the torque sensor 5, and vehicle speed information from CAN. When these signals are input, the microcomputer 41 controls the switching elements 31 to 36 via the pre-driver 42 and the switching elements 61 to 66 via the pre-driver 43 based on the rotation angle of the motor 50. To do.

  Thus, in the present embodiment, the windings 11, 12 and 13, the inverter 30 and the pre-driver 42 constitute a first system, and the windings 51, 52 and 53, the inverter 60 and the pre-driver 43 constitute a second system. It is configured. The first system and the second system are electrically independent. Therefore, even if an electrical abnormality occurs in one system, driving of the motor 50 can be continued by the other system.

Next, the operation of the rotating electrical machine control device 22 of the present embodiment will be described more specifically.
The microcomputer 41 outputs a torque that assists the steering of the steering 4 according to the vehicle speed based on the vehicle speed information from the rotation angle sensor 15, the torque sensor 5, the shunt resistors 37 and 67, and the CAN. The target current value is calculated with respect to the q-axis current flowing through the windings 11, 12, 13, 51, 52 and 53. Here, the microcomputer 41 functions as “target current value calculation means” in the claims.

  The microcomputer 41 generates a pulsed PWM signal for each phase (windings 11, 12, 13, 51, 52, 53) based on the calculated target current value and outputs it to the pre-drivers 42, 43. Here, the microcomputer 41 functions as “PWM signal generating means” in the claims.

  The pre-drivers 42 and 43 generate a pulse signal based on the PWM signal input from the microcomputer 41. This pulse signal is output to the inverter 30 having the switching elements 31 to 36 and the inverter 60 having the switching elements 61 to 66 to control the on / off switching operation of the switching elements 31 to 36 and the switching elements 61 to 66. To do. The voltage of the power supply 8 is applied to each of the windings 11, 12, 13, 51, 52 and 53 by the switching operation of the switching elements 31 to 36 and the switching elements 61 to 66. Here, the pre-drivers 42 and 43 and the inverters 30 and 60 function as “voltage applying means” in the claims.

  When the voltage of the power supply 8 is applied to each of the windings 11, 12, and 13, sinusoidal currents having different phases are applied to the windings 11, 12, 13, 51, 52, and 53 (each phase) of the motor 50. Flow and a rotating magnetic field are generated. In response to this rotating magnetic field, the rotor and the motor shaft 17 rotate together. As the motor shaft 17 rotates, a driving force is output to the gear 3 of the column shaft 2 to assist the driver's steering by the steering 4.

Next, a control method for stopping the driving of the motor 50 by the rotating electrical machine control device 22 of the present embodiment will be described.
In the present embodiment, when the microcomputer 41 performs control to stop the driving of the motor 50, first, the microcomputer 41 functions as a target current value calculation unit, so that all the windings (11, 12, 13, 51, 52, 53) is calculated so that the target current value to be passed becomes a non-zero predetermined value. Here, the non-zero predetermined value is a predetermined value that is not zero and is a small value that does not affect the driving of the motor 50. That is, the predetermined value of current is a small current that does not contribute to the output torque of the motor 50.

  The microcomputer 41 functions as a PWM signal generation unit, and generates a PWM signal for each phase based on the calculated target current value for each phase. Here, since the target current value of each phase is a non-zero value, the pulsed PWM signal generated by the microcomputer 41 is generated so that the rising timing and the falling timing are different. Note that the duty ratio of the PWM signal is about 50%.

  When the PWM signal is output from the microcomputer 41 to the pre-drivers 42 and 43, the switching elements 31 to 36 and 61 to 66 of the inverters 30 and 60 are turned on / off. Thus, a voltage is applied to the windings (11, 12, 13, 51, 52, 53) of each phase at the rising timing of the PWM signal. When a voltage is applied to the windings (11, 12, 13, 51, 52, 53) of each phase substantially at the same time, the timing of applying the voltage due to parasitic capacitance such as a coil component and a resistance component of the motor 50 At the same time, the windings (11, 12, 13, 51, 52, 53) of each phase are simultaneously applied (at the rising timing of the PWM signal) and at the timing of releasing the application of voltage (falling timing of the PWM signal). A common mode current flows (see FIG. 5). The common mode current flows in a spike shape.

  In each phase winding (11, 12, 13, 51, 52, 53), voltage application timing (PWM signal rise timing) and voltage application release timing (PWM signal fall timing) ), A spike-shaped common mode current flows. In this embodiment, since the rising timing and falling timing of the PWM signal are all deviated between the phases of each system, the timing of the flow of the common mode current in each phase is deviated in terms of time. As a result, the total common mode current flowing through the motor 50 is relatively small. Therefore, the generated radio noise is relatively small.

  As described above, in the present embodiment, when the driving of the motor 50 is stopped, the target current value flowing through the windings of all the phases of each system is calculated to be a predetermined non-zero value. The PWM signal is generated so that the pulse change timing of the PWM signal of each phase is different from the pulse change timing of the PWM signal of each other phase. As a result, the inverters 30 and 60 apply voltages so that the application timings of the voltages applied to the windings of all the phases are different from the application timings of the voltages applied to the windings of the other phases. . As a result, the timings at which the common mode currents of the phases flow are all shifted in time, and the sum of the common mode currents flowing through the motor 50 is relatively small. Therefore, radio noise generated when the motor 50 is stopped can be reduced.

(Third embodiment)
A rotating electrical machine control apparatus according to a third embodiment of the present invention will be described. Although the physical configuration of the third embodiment is the same as that of the second embodiment, the control method for stopping the driving of the motor 50 is different from that of the second embodiment.
In the motor 50 to be driven by the rotating electrical machine control apparatus of the present embodiment, for example, the physical constants of the first winding set 101 and the second winding set 102 are the same. When a current of 5 A (ampere) or more is passed as the shaft current, the stopped motor 50 starts to be driven by the generated torque. However, the reason that the physical constants of the two winding sets are equal here is for the sake of simplification and may actually be different.

  In the present embodiment, when the microcomputer 41 performs control to stop the driving of the motor 50, first, the microcomputer 41 functions as a target current value calculation unit, so that the first winding set 101 (windings 11, 12, 13). The target current value to be passed through the second winding set 102 (windings 51, 52, 53) is calculated to be, for example, -3A as the q-axis current, so that the target current value to be passed is, for example, 6A as the q-axis current. Thus, the absolute value differs between the target current value flowing through the first winding set 101 and the target current value flowing through the second winding set 102.

  The microcomputer 41 functions as a PWM signal generation unit, and generates a PWM signal for each phase based on the calculated target current value for each phase. Here, since the target current value of each phase is a relatively large non-zero value, the pulsed PWM signal generated by the microcomputer 41 is generated so that the rising timing and the falling timing are greatly different from each other. Is done. Note that the duty ratio of the PWM signal is a value greatly deviating from 50%.

  When the PWM signal is output from the microcomputer 41 to the pre-drivers 42 and 43, the switching elements 31 to 36 and 61 to 66 of the inverters 30 and 60 are turned on / off. Thus, a voltage is applied to the windings (11, 12, 13, 51, 52, 53) of each phase at the rising timing of the PWM signal.

  As described above, since the target current value to be passed through the first winding set 101 (windings 11, 12, 13) is calculated as 6A as the q-axis current, the q-axis current is included in the first winding set 101. 6A of current flows. On the other hand, since the target current value to be passed through the second winding set 102 (windings 51, 52, 53) is calculated as −3A as the q-axis current, the second winding set 102 includes the first winding set. A current of 3 A flows as a q-axis current so as to generate torque in the opposite direction to 101. Therefore, a current of 3 A substantially flows through the motor 50 and does not exceed the lower limit of the current value at which torque can be generated, so that no torque is generated. Thereby, the rotation of the motor 50 is stopped.

  In each phase winding (11, 12, 13, 51, 52, 53), voltage application timing (PWM signal rise timing) and voltage application release timing (PWM signal fall timing) ), A spike-shaped common mode current flows. In this embodiment, since the rising timing and falling timing of the PWM signal are all greatly deviated between the respective phases of each system, the timings at which the common mode currents flow in the respective phases are largely deviated in terms of time. As a result, the total common mode current flowing through the motor 50 is small. Therefore, the generated radio noise can be reduced.

(Other embodiments)
In the above-described embodiment, an example has been shown in which a rotating electrical machine in which three (three-phase) windings constituting one winding set are connected by Y connection is a control target. On the other hand, in another embodiment of the present invention, a rotating electrical machine in which three windings are connected by delta connection may be controlled. In addition, a rotating electrical machine in which one winding group is configured by two (two-phase) or four (four-phase) windings may be controlled.

  In the first embodiment described above, an example in which a rotating electrical machine having one winding set (one system) is a control target has been described. Moreover, in 2nd Embodiment and 3rd Embodiment, the example which makes control object the rotary electric machine which has two winding groups (2 systems) was shown. On the other hand, in another embodiment of the present invention, a rotating electrical machine having three winding sets (three systems) or more may be controlled. In this case, the rotating electrical machine control device can be configured to include three or more pairs of pre-drivers and inverters according to the number of systems of the rotating electrical machine.

  Further, in the above-described embodiment, when the control means (microcomputer) performs control to stop the driving of the rotating electrical machine, the target current value to be passed through the windings of all the phases is calculated to a predetermined non-zero value. By controlling the target current value calculation means, the PWM signal is generated so that the pulse change timings of the PWM signals of all the phases are different from the pulse change timings of the PWM signals of the other phases. An example of controlling the PWM signal generating means was shown. On the other hand, in another embodiment of the present invention, the control means calculates the target current value to be passed through the winding of at least one phase to a predetermined value that is non-zero when performing control to stop driving of the rotating electrical machine. By controlling the target current value calculation means, the PWM signal is generated so that the pulse change timing of the PWM signal of at least one phase is different from the pulse change timing of the PWM signal of the other phase. The PWM signal generation means may be controlled as described above.

  In the above-described embodiment, when the control unit (microcomputer) performs control to stop the driving of the rotating electrical machine, the PWM signal generation unit performs both the rising timing of the PWM signal and the falling timing of the PWM signal. An example is shown in which PWM signals are generated so as to be different from each other. On the other hand, in another embodiment of the present invention, the PWM signal generation means may generate the PWM signal so that one of the rising timing of the PWM signal and the falling timing of the PWM signal is different. Good.

  In another embodiment of the present invention, the control means (microcomputer) calculates at least 1 while the target current value calculating means calculates the target current value to be zero when performing control to stop driving of the rotating electrical machine. The PWM signal generation means may be directly controlled so that the PWM signal is generated so that the pulse change timing of the PWM signal of one phase differs from the pulse change timing of the PWM signal of the other phase.

  In another embodiment of the present invention, the control means (microcomputer) calculates at least 1 while the target current value calculating means calculates the target current value to be zero when performing control to stop driving of the rotating electrical machine. Directly control the voltage application means (predriver and inverter) so that the voltage is applied so that the timing of applying the voltage applied to the winding of one phase differs from the timing of applying the voltage applied to the winding of the other phase. It is good as well.

  In the embodiment described above, an example in which a rotating electrical machine is attached to a member that steers a steering wheel of a vehicle and the rotating electrical machine is controlled by the rotating electrical machine control device, that is, the present invention is applied to an electric power steering device as a steering control system. An example to do. On the other hand, in another embodiment of the present invention, a rotating electrical machine may be attached to a member that steers a wheel different from the steering wheel of the vehicle, and the rotating electrical machine may be controlled by the rotating electrical machine control device. Usually, the steering wheel of a vehicle corresponds to the front wheel. Therefore, in the said other embodiment, the structure which attaches a rotary electric machine to the member which steers a rear wheel can be considered. That is, in the other embodiment, the rotating electrical machine control device and the rotating electrical machine constitute a rear wheel steering device as a steering control system (active control system) in, for example, a four-wheel steering vehicle. Also in the other embodiments, the rotating electrical machine control device can reduce radio noise generated when the rotating electrical machine is stopped.

  In another embodiment of the present invention, the first rotating electrical machine is attached to a member that steers the steering wheel of the vehicle, and the second rotating electrical machine is attached to a member that steers a wheel different from the steering wheel of the vehicle. The first rotating electrical machine and the second rotating electrical machine may be controlled by the rotating electrical machine control device. That is, in the other embodiment, the rotating electrical machine control device and the first rotating electrical machine constitute, for example, an electric power steering device, and the rotating electrical machine control device and the second rotating electrical machine constitute, for example, a rear wheel steering device. Is. Also in the other embodiment, the rotary electric machine control device can reduce radio noise generated when the first rotary electric machine and the second rotary electric machine are stopped.

Moreover, in other embodiment of this invention, it is not restricted to the rotary electric machine used as a drive source of an electric power steering apparatus and a rear-wheel steering apparatus, For example, other than a rotary electric machine for driving the drive wheel of a hybrid vehicle, and a vehicle A rotating electrical machine that is used as a drive source for other devices that are mounted may be controlled. In this way, the present invention can reduce radio noise generated when driving of the rotating electrical machine is stopped by using the brushless motor (rotating electrical machine) driven by PWM control.
Thus, the present invention is not limited to the above-described embodiment, and can be applied to other various embodiments without departing from the gist thereof.

21, 22 ... rotating electrical machine control device 11, 12, 13, 51, 52, 53 ... winding 101 ... first winding set (winding set)
102 ... 2nd winding set (winding set)
10, 50 ... Motor (rotary electric machine)
41... Microcomputer (target current value calculation means, PWM signal generation means, control means)
42, 43 ... Pre-driver (voltage application means)
30, 60 ... Inverter (voltage application means)

Claims (9)

A rotating electrical machine control device for controlling a rotating electrical machine having a winding set consisting of a plurality of phases of windings,
Target current value calculating means for calculating a target current value to be passed through the winding;
PWM signal generating means for generating a pulsed PWM signal for each winding based on the target current value calculated by the target current value calculating means;
Voltage applying means for applying a voltage to the winding based on the PWM signal generated by the PWM signal generating means;
Control means for controlling the drive of the rotating electrical machine by controlling the target current value calculating means, the PWM signal generating means, and the voltage applying means,
The control means is configured to calculate the target current value so that the target current value to be passed through the winding of at least one phase is calculated to be a non-zero predetermined value when performing control to stop driving of the rotating electrical machine. The PWM signal generation so that the PWM signal is generated so that the timing of the pulse change of the PWM signal of at least one phase differs from the timing of the pulse change of the PWM signal of the other phase by controlling A rotating electrical machine control device characterized by controlling the means.   When the control means performs control to stop driving of the rotating electrical machine, the pulse change timings of the PWM signals of all the phases and the pulse change timings of the PWM signals of the other phases are both 2. The rotating electrical machine control device according to claim 1, wherein the PWM signal generation means is controlled so that the PWM signals are generated differently.   3. The rotating electrical machine control device according to claim 1, wherein the pulse change timing is at least one of a rising timing of the PWM signal and a falling timing of the PWM signal. The control means calculates the target current value calculation means so that the target current value to be passed through the windings of all the phases is calculated to a non-zero predetermined value when performing control to stop driving of the rotating electrical machine. By controlling the PWM signal, the PWM signal is generated so that the timing of the pulse change of the PWM signal of all the phases differs from the timing of the pulse change of the PWM signal of the other phases. The rotating electrical machine control device according to any one of claims 1 to 3, wherein the PWM signal generation unit is controlled. The control means, when controlling to stop the driving of the rotating electrical machine, the application timing of the voltage applied to the winding of at least one phase, the application timing of the voltage applied to the winding of the other phase rotating electric machine control device according to any one of claims 1 to 4, characterized in that to control the voltage application means to apply a differently voltage. When the control means controls to stop driving the rotating electrical machine, the application timing of the voltage applied to the windings of all the phases and the application timing of the voltage applied to the windings of the other phases The rotating electrical machine control device according to claim 5 , wherein the voltage application unit is controlled so as to apply a voltage so as to be different from each other. The rotating electrical machine control device according to any one of claims 1 to 6 ,
The rotating electrical machine attached to a member for turning the steering wheel of the vehicle;
Steering control system with The rotating electrical machine control device according to any one of claims 1 to 6 ,
The rotating electrical machine attached to a member for turning a wheel different from the steering wheel of the vehicle;
Steering control system with The rotating electrical machine control device according to any one of claims 1 to 6 ,
A first rotating electrical machine attached to a member for turning a steering wheel of a vehicle;
A second rotating electrical machine attached to a member for turning a wheel different from the steering wheel;
Steering control system with

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